Liquid hydrocarbon fuels containing Mannich bases or derivatives thereof

ABSTRACT

Fuels with improved dispersancy, anti-icing and rust inhibiting properties contain a compound prepared by the Mannich reaction between a hydroxy-substituted aromatic compound, usually an alkylphenol in which the alkyl group contains at least about six carbon atoms; formaldehyde or a reversible polymer thereof; and a hydroxyalkyl-substituted amine such as diethanolamine. Also useful as additives are the epoxide adducts of such compounds.

United States Patent [191 Dix [ Apr. 15, 1975 1 LIQUID HYDROCARBON FUELS CONTAINING MANNICH BASES OR DERIVATIVES THEREOF [75] Inventor: Robert Wayne Dix,

Mentor-on-the-Lake, Ohio [73] Assignee: The Lubrizol Corporation,

Wickliffe, Ohio [22] Filed: Nov. 7, 1973 [21] Appl. N0.: 413,488

3,297,597 1/1967 Edwards et a1 260/75 TN 3,413,347 11/1968 Worrel 260/570.5 3,649,229 3/1972 Otto 44/73 Primary Examiner-Delbert E. Gantz Assistant Examiner-J. Vaughn Attorney, Agent, or Firm.1ames W. Adams, Jr.; William H. Pittman [57] ABSTRACT Fuels with improved dispersancy, anti-icing and rust inhibiting properties contain a compound prepared by the Mannich reaction between a hydroxy-substituted aromatic compound, usually an alkylphenol in which the alkyl group contains at least about six carbon atoms; formaldehyde or a reversible polymer thereof; and a hydroxyalkyl-substituted amine such as diethanolamine. Also useful as additives are the epoxide adducts of such compounds.

11 Claims, No Drawings LIQUID HYDROCARBON FUELS CONTAINING MANNICH BASES OR DERIVATIVES THEREOF This invention relates to novel liquid hydrocarbon fuels having excellent dispersancy and anti-icing and rust inhibiting properties. More particularly, it relates to compositions comprising a major amount of a liquid hydrocarbon fuel and, dissolved or substantially stably dispersed therein, a minor amount of at least one Mannich base or derivative thereof as specifically described hereinafter.

The increasing demands continually being made on internal combustion engines, from the standpoint of performance, cleanliness and the like, have required the development of more sophisticated fuels for use therein. In particular, it is desired that such fuels be capable of dispersing insoluble impurities, to avoid deposition on engine parts and consequent wear; be resistant to icing at low temperatures; and have decreased tendency to cause rusting and corrosion of engine parts. For these purposes, additives have been developed which impart the requisite qualities to fuels when incorporated therein.

A principal object of the present invention is to provide improved liquid hydrocarbon fuels for internal combustion engines and the like.

A further object is to provide fuels with advantageous dispersancy and rust inhibition properties and decreased susceptibility to icing at low temperatures.

A further object is to provide fuels containing improved additives which impart thereto the properties described above.

Other objects will in part be obvious and will in part appear hereinafter.

As previously noted, the above objects are attained according to this invention by providing a fuel which has incorporated therein a specific Mannich base or derivative thereof. The compounds contemplated are those having the formula wherein R is a monoor polyhydroxy-substituted aromatic, alkylaromatic or (substituted alkyl)aromatic radical; R is hydrogen or a lower alkyl or hydroxysubstituted lower alkyl radical; R is a hydroxysubstituted lower alkyl radical or 1 R R4N/ R is a lower alkylene radical; R is hydrogen or a lower alkyl or hydroxy-substituted lower alkyl radical; R is a hydroxy-substituted lower alkyl radical; and x is the valence of K.

As noted, R is a hydroxy-substituted aromatic radical or the like. Thus, it may be derived from compounds such as phenol, catechol, resorcinol, a-naphthol or B-naphthol. Alkylaromatic radicals derived from these compounds are particularly preferred, especially monoalkylaromatic radicals in which the alkyl group contains at least about six and preferably up to about 100 carbon atoms.

Substituted alkyl groups are considered fully equivalent to the alkyl groups for the purpose of this invention. By substituted" in this sense is meant alkyl groups containing substituents which do not alter significantly their character or reactivity. Examples are:

Ether (especially lower alkoxy) Keto Ester (especially lower carbalkoxy) Aminoacyl (amide) Nitro Thioether Sulfone Sulfonic acid ester, amide, etc.

In general, no more than about three of such substituent groups, and preferably no more than one, will be present for each ten carbon atoms in the alkyl radical.

In the especially preferred compounds used in the fuels of this invention, R is a monohydroxy-substituted alkylaromatic radical in which the alkyl group contains about lO-2O carbon atoms. The integer x is usually 1 or 2 (though it maybe as large as the number of aromatic carbon atoms not otherwise substituted) and is preferably 1; that is, the preferred additive compounds are mono(Mannich bases) of the aromatic or similar materials previously described.

In the preferred compounds, each of R and R is a hydroxy-substituted lower alkyl radical, the term lower alkyl as used herein referring to alkyl radicals containing seven carbon atoms or less. Preferably, these radicals are hydroxyethyl radicals. Any valences of the nitrogen atom which are not satisfied by such radicals are satisfied by hydrogen or lower alkyl.

Also contemplated for use in the fuels of this invention are compounds in which R is wherein R is a lower alkylene (usually an ethylene) radical; R is hydrogen or a lower alkyl or hydroxysubstituted lower alkyl radical and is usually a hydroxyethyl radical; R is a hydroxy-substituted lower alkyl and usually a hydroxyethyl radical. Compounds of this type are derived from the hydroxyalkyl-substituted alkylene diamines such as 2-( 2- aminoethylamino)ethanol.

The Mannich bases used in the fuel compositions of this invention are conveniently prepared by the Mannich reaction between a suitable hydroxyaromatic compound or the like, formaldehyde or a reversible polymer thereof (e.g., paraformaldehyde, trioxane), and an amine of the formula The reaction may be effected at a temperature between room temperature and about 225C., usually about 50200C., with the amounts of the reagents being such as to provide a mole ratio of hydroxyaromatic compound to formaldehyde to amine ranging from about 1:1:1 to about 1:3:3. It is frequently convenient to use an inert diluent, such as an aliphatic or aromatic hydrocarbon (e.g., petroleum fractions, toluene, xylene), to facilitate the reaction. Suitable methods for preparation of the Mannich bases are described in U.S. Pat. Nos. 2,033,092 and 3,297,597, the disclosures of which are incorporated by reference herein.

Also suitable for use in the fuels of this invention are adducts of at least one epoxide with one or more Mannich bases as described above. Such adducts frequently impart demulsification properties to the fuels in addition to the properties previously described.

The epoxide used for preparing the adduct may be, for example, ethylene oxide, propylene oxide, glycidyl ethers, butyl epoxystearate or an epoxide prepared from a commercially available a-olefin mixture in which the olefins contain about 11-14 carbon atoms. Lower alkylene oxides, especially ethylene and propylene oxide, are preferred.

Preparation of the Mannich base-epoxide adducts is accomplished by merely mixing the epoxide with the Mannich base, up to about 20 moles of epoxide being used per mole of Mannich base, and maintaining at a suitable temperature (usually about 25-125C.) for a period of time sufficient to enable the reaction to take place. Reference is made to the above noted US. Pat. No. 3,297,597 for a further description of this reaction.

Typical compounds useful in the fuels of this invention, and methods for their preparation, are illustrated in the following examples. All parts are by weight.

EXAMPLE 1 A solution of 798 parts (3 moles) of tetrapropenesubstituted phenol in 900 parts of xylene is heated to 100C., and 462 parts (4.5 moles) of diethanolamine is added. The mixture is further heated to 120C. and 198 parts (6 moles) of paraformaldehyde is added slowly so as to minimize foaming. After paraformaldehyde addition is complete, the mixture is heated to 140C. for hours while water is removed by distillation. It is then filtered to yield a 40% solution in xylene of the desired Mannich base; the solution contains 2.65% nitrogen.

EXAMPLE 2 A solution of 798 parts (3 moles) of tetrapropenesubstituted phenol in 989 parts of xylene is heated to 100C., and 598 parts (4.5 moles) of diisopropanolamine is added. The mixture is heated to 120C. and 198 parts (6 moles) of paraformaldehyde is added slowly. The temperature is raised to 210C. and held there for 8 hours with removal of water by distillation. Upon filtration, there is obtained a 60% solution in xylene of the desired product. The solution contains 2.13% nitrogen.

EXAMPLE 3 To a solution of 798 parts (3 moles) of tetrapropenesubstituted phenol in 900 parts of xylene at 100C., is added 468 parts (4.5 moles) of 2-(2- aminoethylamino)ethanol. The mixture is heated to 120C. and 198 parts (6 moles) of paraformaldehyde is added slowly. After evolution of water is complete, the mixture is cooled and sufficient xylene is added to provide a 60% solution of the Mannich base therein. Upon filtration, the desired product is obtained containing 2.0% nitrogen.

EXAMPLE 4 A solution of 1257 parts (3 moles) of a polyisobutene-substituted phenol (wherein the polyisobutene substituent has a molecular weight of about 300) in 1321 parts of xylene is heated to C., and 630 parts (6 moles) of diethanolamine is added followed by 198 parts (6 moles) of paraformaldehyde (added slowly to minimize foaming). The mixture is heated to 145C. for 9 hours as water is removed by distillation, and is then filtered to yield a 60% solution in xylene of the desired Mannich base; the solution contains 2.49% nitrogen.

EXAMPLE 5 A solution of 625 parts (0.5 mole) of a polyisobutenyl phenol having a molecular weight of about 1000 in 489 parts of mineral oil is heated to C., and 25 parts (0.75 mole) of paraformaldehyde is added slowly. The mixture is heated to 160C. for 4 hours as water is removed by distillation, and is then cooled to 90C. and 79 parts (0.75 mole) of diethanolamine is added. The temperature is raised to 120C. and an additional 33 parts (1 mole) of paraformaldehyde is added. The temperature is raised to 160C. and maintained there for 6 hours as water is removed by distillation. The mixture is then filtered to yield a 60% solution'in mineral oil of the desired Mannich base; the solut on contains 0.7% nitrogen.

EXAMPLE 6 A solution of 910 parts (4.74 moles) of heptylphenol in 1358 parts of xylene is heated to 80C., and 997 parts (9.48 moles) of diethanolamine is added. The mixture is heated to 1 10C. and 313 parts (9.48 moles) of paraformaldehyde is added slowly. The mixture is then heated to C. as water is removed by azeotropic distillation. The residue is cooled and filtered to yield the desired product as a 60% solution in xylene containing 3.93% nitrogen.

EXAMPLE 7 A mixture of 423 parts (1.59 moles) of the product of Example 1 and 205 parts of xylene is heated to 100C., and 185 parts (318 moles) of propylene oxide is added. The mixture is heated at 100C. for 16 hours and is then stripped at C./10 mm. Xylene is added to produce a 60% solution of the product therein, which after filtration contains 4.9% hydroxyl.

The fuel compositions of the present invention contain in addition to the Mannich base or derivative thereof described hereinabove, a major proportion of a normally liquid hydrocarbon fuel, usually a petroleum distillate fuel such as an aviation or motor gasoline, diesel fuel or fuel oil as defined by ASTM Specification D396. Particularly preferred is gasoline, that is,

a mixture of hydrocarbons having an ASTM boiling point of about 60C. at the 10% distillation point to about 205C. at the 90% distillation point. Such gasolines are further described in ASTM Specification,

1n the compositions of this invention, the Mannich base is dissolved or substantially stably dispersed in the fuel. It will usually be dissolved therein, but the invention includes fuel compositions (especially those comprising residual fuels) which are stable dispersions (e.g., sols or similar colloids). The amount of Mannich base employed is sufficient to disperse solids, inhibit icing or inhibit rust formation; this amount is usually about 1l0,000 and preferably 4-1000 parts (by weight) per million parts of final composition.

The Mannich bases may be incorporated in the fuel simply by mixing them therewith at the desired concentration. Alternatively, they may be dissolved first in a combustible solvent, particularly a hydrocarbon solvent having a boiling point below about 250C. such as naphtha, benzene, toluene, xylene, gasoline or light mineral oil to obtain a fluid concentrate containing up to about 80% of the Mannich base, and the concentrate may then be added to the fuel to obtain the final fuel composition.

In addition to the Mannich base or derivative thereof, the fuel of this invention may contain other additives known to those skilled in the art. These additives include anti-knock agents such as tetraalkyl lead compounds; lead scavengers such as the haloalkanes; deposit preventers or modifiers such as the triaryl phosphates; dyes; antioxidants such as 2,6-di-tertiary-butyl- 4-methylphenol; auxiliary rust inhibitors such as alkylated succinic acids; auxiliary dispersants such as the reaction products of polyalkylene polyamines with alkylated succinic acids; bacteriostatic agents; gum inhibitors; metal deactivators; upper cylinder lubricants; demulsifiers; dehazers; and the like.

A typical fuel composition of this invention comprises gasoline (which may be leaded or unleaded) containing the following additives, all parts being parts by weight per million parts of the final composition:

What is claimed is:

1. A composition comprising a major amount of a liquid hydrocarbon fuel and, dissolved or substantially stably dispersed therein, a minor amount sufficient to improve dispersancy, anti-icing or rust inhibiting properties thereof of at least one compound of the formula wherein R is a monoor polyhydroxy-substituted aromatic, alkyl-aromatic or (substituted alkyl)aromatic radical; R is hydrogen or a lower alkyl or hydroxysubstituted lower alkyl radical; R is a hydroxysubstituted lower alkyl radical or R is a lower alkylene radical; R is hydrogen or a lower alkyl or hydroxy-substituted lower alkyl radical; R is a hydroxy-substituted lower alkyl radical; and x is the valence of R; with the proviso that the substituents on said substituted radicals do not alter significantly their character or reactivity.

2. A composition according to claim 1 wherein R is a monohydroxy-substituted monoalkylaromatic radical in which the alkyl group contains at least about 6 carbon atoms.

3. A composition according to claim 2 wherein each of R and R is a hydroxyethyl radical.

4. A composition according to claim 2 wherein the alkyl group in R contains about 10-20 carbon atoms.

5. A composition according to claim 4 wherein x is 1 or 2.

6. A composition according to claim 5 wherein each of R and R is a hydroxyethyl radical.

7. A composition according to claim 6 wherein the alkyl group in R is a tetrapropenyl group.

8. A composition comprising a major amount of a liquid hydrocarbon fuel and, dissolved or substantially stably dispersed therein, a minor amount sufficient to improve dispersancy, anti-icing or rust inhibiting properties thereof of at least one adduct of at least one epoxide with one or more compounds of the formula 1 R CH2N R wherein R is a monoor poIyhydroxy-substituted aromatic, alkylaromatic or (substituted alkyl)aromatic radical; R is hydrogen or a lower alkyl or hydroxysubstituted lower alkyl radical; R is a hydroxysubstituted lower alkyl radical or R is a lower alkylene radical; R is hydrogen or a lower alkyl or hydroxy-substituted lower alkyl radical; R is a hydroxy-substituted lower alkyl radical; and x is the valence of R; the mole ratio of said epoxide to said compound of the formula R2 R CH N being up to about 20:1; with the proviso that the substituents on said substituted radicals do not alter significantly their character or reactivity.

9. A composition according to claim 8 wherein the epoxide is a lower alkylene oxide, R is a monohydroxysubstituted monoalkylaromatic radical in which the alkyl group contains at least about 6 carbon atoms, and each of R and R is a hydroxyethyl radical.

10. A composition according to claim 9.wherein the epoxide is ethylene or propylene oxide, and alkyl group in R contains about lO-20 carbon atoms, and x is 1 or 2.

11. A composition according to claim 10 wherein the epoxide is propylene oxide and the alkyl group in R is a tetrapropenyl group. 

1. A COMPOSITION COMPRISING A MAJOR AMOUNT OF A LIQUID HYDROCARBON FUEL AND, DISSOLVED OR SUBSTANTIALLY STABLY DISPERSED THEREIN, A MINOR AMOUNT SUFFICIENT TO IMPROVE DISPERSANCY, ANTI-ICING OR RUST INHIBITING PROPERTIES THEREOF OF AT LEAST ONE COMPOUND OF THE FORMULA
 2. A composition according to claim 1 wherein R1 is a monohydroxy-substituted monoalkylaromatic radical in which the alkyl group contains at least about 6 carbon atoms.
 3. A composition according to claim 2 wherein each of R2 and R3 is a hydroxyethyl radical.
 4. A composition according to claim 2 wherein the alkyl group in R1 contains about 10-20 carbon atoms.
 5. A composition according to claim 4 wherein x is 1 or
 2. 6. A composition according to claim 5 wherein each of R2 and R3 is a hydroxyethyl radical.
 7. A composition according to claim 6 wherein the alkyl group in R1 is a tetrapropenyl group.
 8. A composition comprising a major amount of a liquid hydrocarbon fuel and, dissolved or substantially stably dispersed therein, a minor amount sufficient to improve dispersancy, anti-icing or rust inhibiting properties thereof of at least one adduct of at least one epoxide with one or more compounds of the formula
 9. A composition according to claim 8 wherein the epoxide is a lower alkylene oxide, R1 is a monohydroxy-substituted monoalkylaromatic radical in which the alkyl group contains at least about 6 carbon atoms, and each of R2 and R3 is a hydroxyethyl radical.
 10. A composition according to claim 9 wherein the epoxide is ethylene or propylene oxide, and alkyl group in R1 contains about 10-20 carbon atoms, and x is 1 or
 2. 11. A composition according to claim 10 wherein the epoxide is propylene oxide and the alkyl group in R1 is a tetrapropenyl group. 